Method for clock control of clocked half-rail differential logic with sense amplifier and shut-off

ABSTRACT

Clocked half-rail differential logic circuits with sense amplifier and shut-off are activated by a delayed clock and include a sense amplifier circuit that is triggered by a second delayed clock and a shut-off device. The addition of the sense amplifier circuit, and second delayed clock signal allows the sense amplifier circuit to act as the driver and therefore there is no need for increasing the size of the differential logic network to provide a driver function. The addition of the shut-off device provides a half-rail differential logic circuit with shut-off that does not experience the large or “dip” experienced by prior art half-rail differential logic circuits and is therefore more power efficient.

FIELD OF THE INVENTION

[0001] The present invention relates generally to logic circuits and,more particularly, to half-rail differential logic circuits.

BACKGROUND OF THE INVENTION

[0002] With the emergence of an electronics market that stressesportability, compact size, lightweight and the capability for prolongedremote operation, a demand has arisen for low power circuits andsystems. This demand has motivated circuit designers to depart fromconventional circuit designs and venture into more power efficientalternatives. As part of this effort, half-rail differential logic hasemerged as an important design tool for increasing power efficiency.

[0003] FIG.1 shows a schematic diagram of one embodiment of a clockedhalf-rail differential logic circuit 100 designed according to theprinciples of the invention set forth in patent application Ser. No.09/927,751, entitled “Clocked Half-Rail Differential Logic”, filed Aug.9, 2001, in the name of the present inventor, assigned to the assigneeof the present invention, and incorporated herein by reference, in itsentirety. As seen in FIG. 1, a clock signal CLK is coupled to an inputnode 132 of a clock inverter 134 to yield a clock-not signal CLKBAR atoutput node 136 of clock inverter 134.

[0004] As also seen in FIG.1, clocked half-rail differential logiccircuit 100 includes a first supply voltage 102 coupled to a source, orfirst flow electrode 130, of a PFET 101. The signal CLKBAR is coupled toa control electrode or gate 103 of first PFET 101 and a controlelectrode or gate 129 of a first NFET 109. A drain, or second flowelectrode 104, of first PFET 101 is coupled to both a source, or firstflow electrode 106, of a second PFET 105 and a source, or first flowelectrode 108, of a third PFET 107. A control electrode or gate 116 ofsecond PFET 105 is coupled to a first flow electrode 140 of first NFET109 and an OUTBAR terminal 113. A control electrode or gate 114 of thirdPFET 107 is coupled to a second flow electrode 138 of first NFET 109 andan OUT terminal 111. A drain, or second flow electrode 110, of secondPFET 105 is coupled to OUT terminal 111 and a drain, or second flowelectrode 112, of third PFET 107 is coupled to OUTBAR terminal 113.

[0005] OUT terminal 111 is coupled to a first terminal 118 of a logicnetwork 123 and OUTBAR terminal 113 is coupled to a second terminal 120of logic network 123. Logic network 123 includes any type ofdifferential logic and/or circuitry used in the art including variouslogic gates, logic devices and circuits. Logic network 123 also includesfirst and second IN terminals 151 and 153 that are typically coupled toan OUT and OUTBAR terminal of a previous clocked half-rail differentiallogic circuit with sense amplifier and shut-off stage (not shown).

[0006] Logic network 123 also includes third terminal 122 coupled to adrain, or first flow electrode 124, of a second NFET 125. A gate orcontrol electrode 127 of second NFET 125 is coupled to the signal CLKand a source, or second flow electrode 126, of second NFET 125 iscoupled to a second supply voltage 128.

[0007] A particular embodiment of a clocked half-rail differential logiccircuit 100 is shown in FIG.1. Those of skill in the art will recognizethat clocked half-rail differential logic circuit 100 can be easilymodified. For example, different transistors, i.e., first, second andthird PFETs 101, 105 and 107 or first and second NFETs 109 and 125 canbe used. In particular, the NFETs and PFETS shown in FIG.1 can bereadily exchanged for PFETs and NFETs by reversing the polarities of thesupply voltages 102 and 128, or by other well known circuitmodifications. Consequently, the clocked half-rail differential logiccircuit 100 that is shown in FIG. 1 is simply used for illustrativepurposes.

[0008] Clocked half-rail differential logic circuit 100 has two modes,or phases, of operation; a pre-charge phase and an evaluation phase. Inone embodiment of a clocked half-rail differential logic circuit 100, inthe pre-charge phase, the signal CLK is low or a digital “0” and thesignal CLKBAR is high or a digital “1”. Consequently, first PFET 101 andsecond NFET 125 are not conducting or are “off” and logic network 123 isisolated from first supply voltage 102 and second supply voltage 128. Inaddition, during the pre-charge phase, first NFET 109 is conducting oris “on” and, therefore, OUT terminal 111 is shorted to OUTBAR terminal113. Consequently, the supply voltage to logic network 123 isapproximately half the supply voltage 102, i.e., for a first supplyvoltage 102 of Vdd and a second supply voltage 128 of ground, logicnetwork 123 operates at around Vdd/2. During precharge, second and thirdPFETs 105 and 107 are typically not performing any function.

[0009] In one embodiment of a clocked half-rail differential logiccircuit 100, in the evaluation phase, the signal CLK is high or adigital “1” and the signal CLKBAR is low or a digital “0”. Consequently,first PFET 101 and second NFET 125 are conducting or are “on” and firstNFET 109 is not conducting or is “off”. Consequently, depending on theparticular logic in logic network 123, either second PFET 105, or thirdPFET 107, is conducting or is “on” and the other of second PFET 105, orthird PFET 107, is not conducting or is “off”. As a result, either OUTterminal 111 goes from approximately half first supply voltage 102 toapproximately second supply voltage 128 or OUTBAR terminal 113 goes fromapproximately half first supply voltage 102 to approximately firstsupply voltage 102, i.e., for a first supply voltage 102 of Vdd and asecond supply voltage 128 of ground, OUT terminal 111 goes fromapproximately Vdd/2 to zero and OUTBAR terminal 113 goes fromapproximately Vdd/2 to Vdd.

[0010] Clocked half-rail differential logic circuit 100 marked asignificant improvement over prior art half-rail logic circuits in partbecause clocked half-rail differential logic circuit 100 does notrequire the complex control circuit of prior art half-rail differentiallogic circuits and is therefore simpler, saves space and is morereliable than prior art half-rail differential logic circuits. As aresult, clocked half-rail differential logic circuits 100 are bettersuited to the present electronics market that stresses portability,compact size, lightweight and the capability for prolonged remoteoperation. However, clocked half-rail differential logic circuit 100 hassome limitations.

[0011] For instance, clocked half-rail differential logic circuit 100worked very well under conditions of a light load, for instance underconditions where fan out was less than four. However, clocked half-raildifferential logic circuit 100 was less useful under conditions of aheavy load, for instance, in cases where fan out exceeded four. Theshortcomings of clocked half-rail differential logic circuit 100 aroseprimarily because under heavy load conditions logic network 123, and thetransistors and components making up logic network 123, had to beincreased in size to act as a driver for the next stage in the cascade.This in turn meant that logic network 123 was large, slow andinefficient. The problem was further aggravated as additional clockedhalf-rail differential logic circuits 100 were cascaded together to formthe chains commonly used in the industry. Consequently, the fullpotential of clocked half-rail differential logic circuit 100 was notrealized and its use was narrowly limited to light load applications.

[0012] In addition during the evaluation phase, clocked half-raildifferential logic circuit 100 drew excess power unnecessarily as therelevant inputs, 151 or 153, to logic network 123 were transitioning lowto shut off the path of one of the complementary OUT terminals, OUTterminal 111 or OUTBAR terminal 113, to ground. The high OUT terminal,OUT terminal 111 or OUTBAR terminal 113, therefore experienced a “dip”or pre-charged high, during the transition when the inputs 151 or 153switched from high to low and a short circuit current, or crossbarcurrent, path was established from Vdd 102 to ground. This “dip” orpre-charged high was undesirable and resulted in significant power beingwasted.

[0013] In addition, the structure of clocked half-rail differentiallogic circuit 100 was particularly susceptible to noise. This problemwas extremely undesirable, and damaging, since, as discussed above,typically, multiple clocked half-rail differential logic circuits 100were cascaded in long chains (not shown) of clocked half-raildifferential logic circuits 100. In these chain configurations, thesusceptibility of clocked half-rail differential logic circuit 100 tonoise meant that each successive stage of the chain contributedadditional noise and was even more adversely affected by the noise thanthe previous stage. Consequently, a few stages into a chain of clockedhalf-rail differential logic circuits 100 noise became the dominantfactor in the chain.

[0014] What is needed is a method and apparatus for creating half-raildifferential logic circuits that are capable of efficient use underheavy loads and are therefore more flexible, more space efficient andmore reliable than prior art half-rail differential logic circuits. Inaddition, a half-rail differential logic circuit is needed that does notexperience the large “dip” experienced by clocked half-rail differentiallogic circuit 100 and is therefore more power efficient. Finally, it isdesirable to have a half-rail differential logic circuit that is moreresistant to noise than clocked half-rail differential logic circuitwith sense amplifier and shut-off 100.

SUMMARY OF THE INVENTION

[0015] The clocked half-rail differential logic circuits with senseamplifier and shut-off of the invention include a sense amplifiercircuit that is triggered by the delayed clock of the following stage,i.e., the clock input to the sense amplifier circuit of the clockedhalf-rail differential logic circuit with sense amplifier and shut-offof the invention is additionally delayed with respect to the delayedclock that drives the clocked half-rail differential logic. The additionof the sense amplifier circuit, and second delayed clock signal,according to the invention, allows the sense amplifier circuit to act asthe driver and therefore there is no need for increasing the size of thelogic network, and the transistors and components making up the logicnetwork, to provide the driver function. Consequently, the clockedhalf-rail differential logic circuits with sense amplifier and shut-offof the invention are capable of operating efficiently under heavy loadconditions without the increased size and the significant reduction inspeed associated with prior art half-rail differential logic circuits.In addition, the clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention require less space, aresimpler, dissipate less heat and have fewer components to potentiallyfail.

[0016] In addition, according to the present invention, clockedhalf-rail differential logic circuits with sense amplifier and shut-offinclude shut-off devices to minimize the “dip” at the high output nodethat was associated with prior art clocked half-rail differential logiccircuits. The shut-off device of the invention isolates the high OUTterminal immediately from the IN terminals when the complementary OUTterminal is pulled to ground. Consequently, according to the presentinvention, the window period, or path, for the short circuit current, orcrossbar current, is significantly decreased and power is saved.

[0017] In addition, since clocked half-rail differential logic circuitswith sense amplifier and shut-off of the invention include a shut-offdevice, the high OUT terminal is isolated from the IN terminals and thenoise immunity of the clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention is significantly betterthan prior art clocked half-rail differential logic circuits becausenoise on the IN terminal does not affect the high OUT terminal afterevaluation. Consequently, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention are bettersuited for application in cascaded chains.

[0018] As discussed above, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention can becascaded together to form the chains commonly used in the industry. Whenthe clocked half-rail differential logic circuits with sense amplifierand shut-off of the invention are cascaded together, the advantages ofthe clocked half-rail differential logic circuits with sense amplifierand shut-off of the invention are particularly evident and the gains interms of noise immunity, power efficiency, size reduction andflexibility are further pronounced.

[0019] In particular, one embodiment of the invention is a cascadedchain of clocked half-rail differential logic circuits with senseamplifier and shut-off. The chain includes a first clocked half-raildifferential logic circuit with sense amplifier and shut-off. The firstclocked half-rail differential logic circuit with sense amplifier andshut-off includes: a first clocked half-rail differential logic circuitwith sense amplifier and shut-off first clock in terminal; at least onefirst clocked half-rail differential logic circuit with sense amplifierand shut-off data IN terminal; at least one first clocked half-raildifferential logic circuit with sense amplifier and shut-off data OUTterminal; and a first clocked half-rail differential logic circuit withsense amplifier and shut-off second clock in terminal.

[0020] The cascaded chain of the invention also includes a secondclocked half-rail differential logic circuit with sense amplifier andshut-off. The second clocked half-rail differential logic circuit withsense amplifier and shut-off includes: a second clocked half-raildifferential logic circuit with sense amplifier and shut-off first clockin terminal; at least one second clocked half-rail differential logiccircuit with sense amplifier and shut-off data IN terminal; at least onesecond clocked half-rail differential logic circuit with sense amplifierand shut-off data OUT terminal; and a second clocked half-raildifferential logic circuit with sense amplifier and shut-off secondclock in terminal.

[0021] According to the invention, the at least one first clockedhalf-rail differential logic circuit with sense amplifier and shut-offdata OUT terminal is coupled to the at least one second clockedhalf-rail differential logic circuit with sense amplifier and shut-offdata IN terminal to form the chain. According to the invention, a firstclock signal is coupled to the first clocked half-rail differentiallogic circuit with sense amplifier and shut-off first clock in terminaland a second clock signal is coupled to the first clocked half-raildifferential logic circuit with sense amplifier and shut-off secondclock in terminal and the second clocked half-rail differential logiccircuit with sense amplifier and shut-off first clock in terminal.According to the invention, the second clock signal is delayed withrespect to the first clock signal by a predetermined delay time.

[0022] In one embodiment of the invention, a delay circuit is coupledbetween the first clocked half-rail differential logic circuit withsense amplifier and shut-off clock in terminal and the second clockedhalf-rail differential logic circuit with sense amplifier and shut-offfirst clock in terminal to provide the predetermined delay time. In oneembodiment of the invention, the delay circuit is also coupled betweenthe first clocked half-rail differential logic circuit with senseamplifier and shut-off clock in terminal and the first clocked half-raildifferential logic circuit with sense amplifier and shut-off secondclock in terminal to provide the predetermined delay time.

[0023] One embodiment of the invention is a clocked half-raildifferential logic circuit with sense amplifier and shut-off thatincludes a clocked half-rail differential logic circuit with senseamplifier and shut-off OUT terminal and a clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal.

[0024] The clocked half-rail differential logic circuit with senseamplifier and shut-off also includes a first transistor including afirst transistor first flow electrode, a first transistor second flowelectrode and a first transistor control electrode. The first transistorfirst flow electrode is coupled to a first supply voltage.

[0025] The clocked half-rail differential logic circuit with senseamplifier and shut-off also includes a second transistor, the secondtransistor including a second transistor first flow electrode, a secondtransistor second flow electrode and a second transistor controlelectrode. The first transistor second flow electrode is coupled to thesecond transistor first flow electrode and the second transistor secondflow electrode is coupled to the clocked half-rail differential logiccircuit with sense amplifier and shut-off OUT terminal.

[0026] The clocked half-rail differential logic circuit with senseamplifier and shut-off also includes a third transistor, the thirdtransistor including a third transistor first flow electrode, a thirdtransistor second flow electrode and a third transistor controlelectrode. The first transistor second flow electrode is coupled to thethird transistor first flow electrode and the third transistor secondflow electrode is coupled to the clocked half-rail differential logiccircuit with sense amplifier and shut-off OUTBAR terminal.

[0027] The clocked half-rail differential logic circuit with senseamplifier and shut-off also includes a fourth transistor, the fourthtransistor including a fourth transistor first flow electrode, a fourthtransistor second flow electrode and a fourth transistor controlelectrode. The second transistor control electrode is coupled to thefourth transistor first flow electrode and the clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTBARterminal. The third transistor control electrode is coupled to thefourth transistor second flow electrode and the clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal.

[0028] The clocked half-rail differential logic circuit with senseamplifier and shut-off also includes a logic network, the logic networkincluding a logic network first IN terminal, a logic network second INterminal, a logic network OUT terminal, a logic network OUTBAR terminaland a logic network fifth terminal.

[0029] The clocked half-rail differential logic circuit with senseamplifier and shut-off also includes a fifth transistor, the fifthtransistor including a fifth transistor first flow electrode, a fifthtransistor second flow electrode and a fifth transistor controlelectrode. The fifth transistor first flow electrode is coupled to thelogic network fifth terminal and the fifth transistor second flowelectrode is coupled to a second supply voltage.

[0030] A first clock signal CLKA is coupled to the fifth transistorcontrol electrode of the fifth transistor of the clocked half-raildifferential logic circuit with sense amplifier and shut-off. A firstclock-not signal CLKBAR is coupled to the first transistor controlelectrode of the first transistor of the clocked half-rail differentiallogic circuit with sense amplifier and shut-off and the fourthtransistor control electrode of the fourth transistor of the clockedhalf-rail differential logic circuit with sense amplifier and shut-off.

[0031] In one embodiment of the invention, the clocked half-raildifferential logic circuit with sense amplifier and shut-off alsoincludes a sense amplifier circuit coupled between the clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal and the clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal.

[0032] In one embodiment of the invention, the clocked half-raildifferential logic circuit with sense amplifier and shut-off senseamplifier circuit includes a sixth transistor, the sixth transistorincluding a sixth transistor first flow electrode, a sixth transistorsecond flow electrode and a sixth transistor control electrode. Thesecond transistor second flow electrode is coupled to the sixthtransistor first flow electrode. The sixth transistor second flowelectrode is coupled to a first node. The sixth transistor controlelectrode is coupled to the fourth transistor second flow electrode andthe clocked half-rail differential logic circuit with sense amplifierand shut-off OUTBAR terminal.

[0033] In one embodiment of the invention, the clocked half-raildifferential logic circuit with sense amplifier and shut-off senseamplifier circuit also includes a seventh transistor, the seventhtransistor including a seventh transistor first flow electrode, aseventh transistor second flow electrode and a seventh transistorcontrol electrode. The third transistor second flow electrode is coupledto the seventh transistor first flow electrode. The seventh transistorsecond flow electrode is coupled to a first node. The seventh transistorcontrol electrode is coupled to the third transistor second flowelectrode and the clocked half-rail differential logic circuit withsense amplifier and shut-off OUT terminal.

[0034] In one embodiment of the invention, the clocked half-raildifferential logic circuit with sense amplifier and shut-off senseamplifier circuit also includes an eighth transistor, the eighthtransistor including an eighth transistor first flow electrode, aneighth transistor second flow electrode and an eighth transistor controlelectrode. The eighth transistor first flow electrode is coupled to thefirst node and the eighth transistor second flow electrode is coupled toa second supply voltage. A second clock signal CLKB is coupled to theeighth transistor control electrode of the clocked half-raildifferential logic with circuit sense amplifier circuit. In oneembodiment of the invention, the second clock signal CLKB is delayed apredetermined time with respect to the first clock signal CLKA.

[0035] In one embodiment of the invention, the clocked half-raildifferential logic circuit with sense amplifier and shut-off alsoincludes a shut-off device coupled between the clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal and the clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal and the logic network OUTterminal and logic network OUTBAR terminal.

[0036] In one embodiment of the invention, the clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice includes a ninth transistor, the ninth transistor including aninth transistor first flow electrode, a ninth transistor second flowelectrode and a ninth transistor control electrode. The secondtransistor second flow electrode is coupled to the ninth transistorfirst flow electrode. The ninth transistor second flow electrode iscoupled to the logic network OUT terminal. The ninth transistor controlelectrode is coupled to the fourth transistor first flow electrode andthe clocked half-rail differential logic circuit with sense amplifierand shut-off OUTBAR terminal.

[0037] In one embodiment of the invention, the clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice also includes a tenth transistor, the tenth transistor includinga tenth transistor first flow electrode, a tenth transistor second flowelectrode and a tenth transistor control electrode. The third transistorsecond flow electrode is coupled to the tenth transistor first flowelectrode. The tenth transistor second flow electrode is coupled to thelogic network OUTBAR terminal. The tenth transistor control electrode iscoupled to the fourth transistor second flow electrode and the clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal.

[0038] As discussed in more detail below, the clocked half-raildifferential logic circuits with sense amplifier and shut-off of theinvention are capable of efficient use under heavy loads and aretherefore more flexible, more space efficient and more reliable thanprior art half-rail differential logic circuits. In addition, thepresent invention provides a half-rail differential logic circuit withshut-off that does not experience the large “dip” experienced by priorart half-rail differential logic circuits and is therefore more powerefficient. In addition, the present invention provides a half-raildifferential logic circuit with shut-off that is more resistant to noisethan prior art half-rail differential logic circuits.

[0039] It is to be understood that both the foregoing generaldescription and following detailed description are intended only toexemplify and explain the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which are incorporated in, andconstitute a part of this specification, illustrate embodiments of theinvention and, together with the description, serve to explain theadvantages and principles of the invention. In the drawings:

[0041]FIG. 1 shows a schematic diagram of a clocked half-raildifferential logic circuit;

[0042]FIG. 2 shows a schematic diagram of one embodiment of a clockedhalf-rail differential logic circuit with sense amplifier and shut-offdesigned according to the principles of the present invention;

[0043]FIG. 3 shows one embodiment of a cascaded chain of clockedhalf-rail differential logic circuits with sense amplifier and shut-offaccording to the principles of the present invention; and

[0044]FIG. 4 is a one embodiment of a timing diagram for the cascadedchain of clocked half-rail differential logic circuits with senseamplifier and shut-off of the invention shown in FIG. 3.

DETAILED DESCRIPTION

[0045] The invention will now be described in reference to theaccompanying drawings. The same reference numbers may be used throughoutthe drawings and the following description to refer to the same or likeparts.

[0046] The clocked half-rail differential logic circuits with senseamplifier and shut-off (200 in FIG. 2) of the invention include a senseamplifier circuit (280 in FIG. 2) that is triggered by the delayed clockof the following stage, i.e., the clock input (327A, 327B, 327C and 327Nin FIG. 3) to the sense amplifier circuit of the clocked half-raildifferential logic circuits with sense amplifier and shut-off of theinvention is additionally delayed with respect to the delayed clock (361371, 381 and 391 in FIG. 3) that drives the half-rail differentiallogic. The addition of the sense amplifier circuit, and second delayedclock signal, according to the invention, allows the sense amplifiercircuit to act as the driver and therefore there is no need forincreasing the size of the logic network (223 in FIG. 2) to provide thedriver function. Consequently, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention are capableof operating efficiently under heavy load conditions without theincreased size and the significant reduction in speed associated withprior art half-rail differential logic circuits (100 in FIG. 1).

[0047] In addition, according to the present invention, clockedhalf-rail differential logic circuits with sense amplifier and shut-offinclude shut-off devices (290A and 290B in FIG. 2) to minimize the “dip”at the high output node that was associated with prior art clockedhalf-rail differential logic circuits. The shut-off device of theinvention isolates the high terminal (211 or 213 in FIG. 2) immediatelyfrom the IN terminals (251 and 253 in FIG. 3) when the complementary OUTterminal is pulled to ground. Consequently, according to the presentinvention, the window period, or path, for the short circuit current, orcrossbar current, is significantly decreased and power is saved.

[0048] In addition, since clocked half-rail differential logic circuitswith sense amplifier and shut-off include a shut-off device, the highOUT terminal is isolated from the IN terminals and the noise immunity ofthe clocked half-rail differential logic circuits with sense amplifierand shut-off of the invention is significantly better than prior artclocked half-rail differential logic circuits because noise on the INterminal does not affect the high OUT terminal after evaluation.Consequently, the clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention are better suited forapplication in cascaded chains (301 in FIG. 3).

[0049] As discussed above, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention can becascaded together to form the chains (301 in FIG. 3) commonly used inthe industry. When the clocked half-rail differential logic circuitswith sense amplifier and shut-off of the invention are cascadedtogether, the advantages of the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention areparticularly evident and the gains in terms of noise immunity, powerefficiency, size reduction and flexibility are further pronounced.

[0050]FIG. 2 shows a schematic diagram of one embodiment of a clockedhalf-rail differential logic circuit with sense amplifier and shut-off200 designed according to the principles of the present invention. Asseen in FIG. 2, a clock signal CLKA is coupled to an input node 232 of aclock inverter 234 to yield a clock-not signal CLKBAR at output node 236of clock inverter 234.

[0051] As also seen in FIG. 2, clocked half-rail differential logiccircuit with sense amplifier and shut-off 200 includes a first supplyvoltage 202 coupled to a source, or first flow electrode 230, of a PFET201. The signal CLKBBAR is coupled to a control electrode or gate 203 ofPFET 201 and a control electrode or gate 229 of a NFET 209. A drain, orsecond flow electrode 204, of PFET 201 is coupled to both a source, orfirst flow electrode 206, of a PFET 205 and a source, or first flowelectrode 208, of a PFET 207. A control electrode or gate 216 of PFET205 is coupled to a first flow electrode 240 of NFET 209 and an OUTBARterminal 213. A control electrode or gate 214 of PFET 207 is coupled toa second flow electrode 238 of NFET 209 and an OUT terminal 211. Adrain, or second flow electrode 210, of PFET 205 is coupled to OUTterminal 211 and a drain, or second flow electrode 212, of PFET 207 iscoupled to OUTBAR terminal 213.

[0052] Clocked half-rail differential logic circuit with sense amplifierand shut-off 200 includes a logic network 223. Logic network 223includes any type of differential logic and/or circuitry used in the artincluding various logic gates, logic devices and circuits. Logic network223 includes first and second IN terminals 251 and 253 that aretypically coupled to an OUT and OUTBAR terminal of a previous clockedhalf-rail differential logic circuit with sense amplifier and shut-offstage (not shown) and logic network OUT terminal 218 and OUTBAR terminal220.

[0053] Logic network 223 also includes third terminal 222 coupled to adrain, or first flow electrode 224, of a NFET 225. A gate or controlelectrode 227 of NFET 225 is coupled to the signal CLKA and a source, orsecond flow electrode 226, of NFET 225 is coupled to a second supplyvoltage 271.

[0054] According to the invention, clocked half-rail differential logiccircuit with sense amplifier and shut-off 200 also includes senseamplifier circuit 280. In one embodiment of the invention, senseamplifier circuit 280 includes a sixth transistor, NFET 215, including adrain 251, a source 253 and a control electrode or gate 252. Drain 210of PFET 205 is coupled to drain 251 of NFET 215. Source 253 of NFET 215is coupled to a first node 255. Gate 252 of NFET 215 is coupled tosource 240 of NFET 209 and clocked half-rail differential logic circuitwith sense amplifier and shut-off OUTBAR terminal 213.

[0055] In one embodiment of the invention, sense amplifier circuit 280also includes a seventh transistor, NFET 217, including a drain 259, asource 257 and a control electrode or gate 258. Drain 212 of PFET 207 iscoupled to drain 259 of NFET 217. Source 257 of NFET 217 is coupled tofirst node 255. Gate 258 of NFET 217 is coupled to drain 238 of NFET 209and clocked half-rail differential logic circuit with sense amplifierand shut-off OUT terminal 211.

[0056] In one embodiment of the invention, sense amplifier circuit 280of clocked half-rail differential logic circuit with sense amplifier andshut-off 200 also includes an eighth transistor, NFET 270, including adrain 218, a source 221 and a control electrode or gate 277. Drain 218of NFET 270 is coupled to first node 255. Source 221 of NFET 270 iscoupled to second supply voltage 271. A delayed, or second, clock signalCLKB is coupled to control electrode or gate 277 of NFET 270. Accordingto one embodiment of the invention, clock signal CLKB is delayed withrespect to clock signal CLKA by a predetermined time.

[0057] According to the invention, clocked half-rail differential logiccircuit with sense amplifier and shut-off 200 also includes shut-offdevice 290A/290B. In one embodiment of the invention, shut-off device290A/290B includes a ninth transistor, NFET 281 including a drain 283, asource 285 and a control electrode or gate 287. Drain 210 of PFET 205 iscoupled to drain 283 of NFET 281. Source 285 of NFET 281 is coupled toOUT terminal 218 of logic network 223. Gate 287 of NFET 281 is coupledto source 240 of NFET 209 and clocked half-rail differential logiccircuit with sense amplifier and shut-off OUTBAR terminal 213.

[0058] In one embodiment of the invention, shut-off device 290A/290Balso includes a tenth transistor, NFET 291 including a drain 293, asource 295 and a control electrode or gate 297. Drain 212 of PFET 207 iscoupled to drain 293 of NFET 291. Source 295 of NFET 291 is coupled toOUTBAR terminal 220 of logic network 223. Gate 297 of NFET 291 iscoupled to drain 238 of NFET 209 and clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal 211.

[0059] A particular embodiment of a clocked half-rail differential logiccircuit with sense amplifier and shut-off 200 is shown in FIG. 2. Thoseof skill in the art will recognize that clocked half-rail differentiallogic circuit with sense amplifier and shut-off 200 can be easilymodified. For example, different transistors, i.e., PFETs 201, 205 and207 or NFETs 209, 215, 217, 225, 270, 281 and 291 can be used. Inparticular, the NFETs and PFETS shown in FIG. 2 can be readily exchangedfor PFETs and NFETs by reversing the polarities of the supply voltages202 and 271, or by other well known circuit modifications. Consequently,the clocked half-rail differential logic circuit with sense amplifierand shut-off 200 that is shown in FIG. 2 is simply used for illustrativepurposes.

[0060] As discussed above, clocked half-rail differential logic circuitwith sense amplifier and shut-off 200 of the invention includes senseamplifier circuit 280 that is triggered by delayed, or second, clocksignal CLKB of the following stage, i.e., the clock signal CLKB to gate277 of NFET 270 of sense amplifier circuit 280 is additionally delayedwith respect to the first clock signal CLKA. As also noted above, Clocksignal CLKA is coupled to control electrode 277 of NFET 270. Clock-notsignal CLKABAR is coupled to gate 203 of PFET 201 and gate 229 of NFET209. The addition of sense amplifier circuit 280 and second delayedclock signal CLKB, according to the invention, allows sense amplifiercircuit 280 to act as the driver circuit and therefore there is no needfor increasing the size of the logic network 223, or the components oflogic network 223, to provide the driver function. Consequently, clockedhalf-rail differential logic circuit with sense amplifier and shut-off200 of the invention is capable of operating efficiently under heavyload conditions without the significant reduction in speed associatedwith half-rail differential logic circuits 100. In addition, clockedhalf-rail differential logic circuit with sense amplifier and shut-off200 requires less space, is simpler, dissipates less heat and has fewercomponents to potentially fail.

[0061] The addition of shut-off device 290A/290B, according to thepresent invention, allows clocked half-rail differential logic circuitwith sense amplifier and shut-off 200 to minimize the “dip” at the highterminal 211 or 213 that was associated with prior art clocked half-raildifferential logic circuits (100 in FIG. 1). In operation, during thepre-charge phase, i.e., when signal CLKA is low, PFETs 205 and 207 areoff and shut-off device NFETs 281 and 291 are on, or conduct.

[0062] During evaluation, i.e., when signal CLKA is high, one of clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal 211 or clocked half-rail differential logic circuit withsense amplifier and shut-off OUTBAR terminal 213 is discharged throughlogic network 223 and the other one of clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal 213 orclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal 211 is pulled up, after experiencing a slight dipcaused by the IN terminals 251 and/or 253 continuing to transition low.Whichever one of the shut-off device NFETs 281 and 291 is controlled bythe low terminal, i.e., either clocked half-rail differential logiccircuit with sense amplifier and shut-off OUT terminal 211 or clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal 213, will then turn off and isolate the complementaryhigh terminal, i.e., clocked half-rail differential logic circuit withsense amplifier and shut-off OUTBAR terminal 213 or clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal 211. Whichever one of either clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal 211 orclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal 213 is low, that low terminal will also causeone of either PFET 205 or 207 to turn on or conduct. Consequently, thecross-coupled connection of PFETs 205 and 207 provides a latch-likefunction to maintain the voltage level after evaluation.

[0063] In short, shut-off device 290A/290B of the invention isolates thehigh OUT terminal (211 or 213) immediately from the IN terminals (251and 253) when the complementary OUT terminal (213 or 211) is pulled toground. Consequently, according to the present invention, the windowperiod, or path, for the short circuit current, or crossbar current, issignificantly decreased and power is saved.

[0064] In addition, since clocked half-rail differential logic circuitswith sense amplifier and shut-off 200 include shut-off device 290A/290B,the high OUT terminal (211 or 213) is isolated from IN terminals (251and 253) and the noise immunity of clocked half-rail differential logiccircuits with sense amplifier and shut-off 200 of the invention issignificantly better than prior art clocked half-rail differential logiccircuits because noise on the IN terminals (251 and 253) does not affectthe high OUT terminal (211 or 213) after evaluation. Consequently,clocked half-rail differential logic circuits with sense amplifier andshut-off 200 of the invention are better suited for application incascaded chains.

[0065] As discussed above, clocked half-rail differential logic circuitwith sense amplifier and shut-off 200 can be cascaded together withother clocked half-rail differential logic circuits with sense amplifierand shut-off 200 to form the chains commonly used in the industry. Whenclocked half-rail differential logic circuits with sense amplifier andshut-off 200 of the invention are cascaded together, the advantages ofclocked half-rail differential logic circuit with sense amplifier andshut-off 200 is particularly evident and the gains in terms ofefficiency, size reduction and flexibility are further pronounced.

[0066] When clocked half-rail differential logic circuit with senseamplifier and shut-off 200 of the invention are cascaded together, thefirst clock signal CLKA is, according to the invention, timed to be atleast the delay of the previous clocked half-rail differential logiccircuit with sense amplifier and shut-off 200 (not shown) to ensure eachclocked half-rail differential logic circuit with sense amplifier andshut-off 200 of the invention is switched or “fired” only after it hasreceived an input from the previous clocked half-rail differential logiccircuit with sense amplifier and shut-off 200.

[0067]FIG. 3 shows one embodiment of a cascaded chain 301 of clockedhalf-rail differential logic circuits with sense amplifier and shut-off300A, 300B, 300C and 300N of the present invention. Each clockedhalf-rail differential logic circuit with sense amplifier and shut-off300A, 300B, 300C and 300N represents a stage in cascaded chain 301. Inone embodiment of the invention, each clocked half-rail differentiallogic circuit with sense amplifier and shut-off 300A, 300B, 300C and300N is similar to clocked half-rail differential logic circuit withsense amplifier and shut-off 200 discussed above with respect to FIG. 2.

[0068] As seen in FIG. 3, clocked half-rail differential logic circuitwith sense amplifier and shut-off 300A includes: a first clock interminal 326A; a second clock in terminal 327A; an OUT terminal 311A;and an OUTBAR terminal 313A.

[0069] Clocked half-rail differential logic circuit with sense amplifierand shut-off 300B includes: a first clock in terminal 326B; a secondclock in terminal 327B; an IN terminal 351B, coupled to OUT terminal311A of clocked half-rail differential logic circuit with senseamplifier and shut-off 300A; an INBAR terminal 353B, coupled to OUTBARterminal 313A of clocked half-rail differential logic circuit with senseamplifier and shut-off 300A; an OUT terminal 311B; and an OUTBARterminal 313B. Likewise, clocked half-rail differential logic circuitwith sense amplifier and shut-off 300C includes: a first clock interminal 326C; a second clock in terminal 327C; an IN terminal 351C,coupled to OUT terminal 311B of clocked half-rail differential logiccircuit with sense amplifier and shut-off 300B; an INBAR terminal 353C,coupled to OUTBAR terminal 313B of clocked half-rail differential logiccircuit with sense amplifier and shut-off 300B; an OUT terminal 311C;and an OUTBAR terminal 313C.

[0070] Clocked half-rail differential logic circuit with sense amplifierand shut-off 300N includes: a first clock in terminal 326N; a secondclock in terminal 327N; an IN terminal 351N, coupled to an OUT terminal311N−1 (not shown) of a clocked half-rail differential logic circuitwith sense amplifier and shut-off 300N−1 (not shown); an INBAR terminal353N, coupled to an OUTBAR terminal 313N−1 (not shown) of a clockedhalf-rail differential logic circuit with sense amplifier and shut-off300N−1 (not shown); an OUT terminal 311N; and an OUTBAR terminal 313N.

[0071] According to the invention, any number of clocked half-raildifferential logic circuits with sense amplifier and shut-off 300A,300B, 300C and 300N can be employed with cascaded chain 301. As alsoshown in FIG. 3, and discussed above, OUT terminal 311A of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300A couples signal OUTA to IN terminal 351B of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300B andOUTBAR terminal 313A of clocked half-rail differential logic circuitwith sense amplifier and shut-off 300A couples signal OUTBARA to INBARterminal 353B of clocked half-rail differential logic circuit with senseamplifier and shut-off 300B. Likewise, OUT terminal 311B of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300B couples signal OUTB to IN terminal 351C of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300C andOUTBAR terminal 313B of clocked half-rail differential logic circuitwith sense amplifier and shut-off 300B couples signal OUTBARB to INBARterminal 353C of clocked half-rail differential logic circuit with senseamplifier and shut-off 300C. In addition, OUT terminal 311N of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300N couples signal OUTN to an IN terminal 351N+1 (not shown) of aclocked half-rail differential logic circuit with sense amplifier andshut-off 300N+1 (not shown) and OUTBAR terminal 313N of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300N couples signal OUTBARN to an INBAR terminal 353N+1 (not shown) of aclocked half-rail differential logic circuit with sense amplifier andshut-off 300N+1 (not shown).

[0072] According to the invention, each clocked half-rail differentiallogic circuit with sense amplifier and shut-off 300A, 300B, 300C and300N of cascaded chain 301 receives its own delayed first clock signalCLKA 361, CLKB 371, CLKC 381 and CLKN 391, respectively. According tothe invention clock signals CLKA 361, CLKB 371, CLKC 381 and CLKN 391are provided to clocked half-rail differential logic circuit with senseamplifier and shut-off 300A, 300B, 300C and 300N, respectively, byintroducing delay circuits 363, 373, 383 and 393 between successiveclocked half-rail differential logic circuits with sense amplifier andshut-off 300A, 300B, 300C and 300N. Consequently, delay circuit 363introduces a delay time between signal CLKA 361, coupled to first clockin terminal 326A of clocked half-rail differential logic circuit withsense amplifier and shut-off 300A, and signal CLKB 371, coupled to firstclock in terminal 326B of clocked half-rail differential logic circuitwith sense amplifier and shut-off 300B. Delay circuit 373 introduces adelay time between signal CLKB 371 and signal CLKC 381, coupled to firstclock in terminal 326C of clocked half-rail differential logic circuitwith sense amplifier and shut-off 300C. Two delay circuits 363 and 373introduce two delay times between signal CLKA 361 and signal CLKC 381.Likewise, a series of N−1 delay circuits, and N−1 delay times, existsbetween signal CLKA 361 and signal CLKN 391, coupled to first clock interminal 326N of clocked half-rail differential logic circuit with senseamplifier and shut-off 300N, and a further delay circuit 393 introducesa further delay time between CLKN 391 and CLK N+1 (not shown) coupled toa first clock in terminal 326N+1 (not shown) of a clocked half-raildifferential logic circuit with sense amplifier and shut-off 300N+1 (notshown).

[0073] Delay circuits 363, 373, 383 and 393 are any one of many delaycircuits known in the art such as inverters, or groups of inverters,gates, transistors or any other elements that introduce a time delay.According to the invention, delay circuits 363, 373, 383 and 393 areused to ensure the activation of each stage, i.e., each clockedhalf-rail differential logic circuit with sense amplifier and shut-off300A, 300B, 300C and 300N, is timed such that the delay of the clock islonger than the evaluation duration of the previous stage. In oneembodiment of the invention, the delayed clock signals CLKA 361, CLKB371, CLKC 381 and CLKN 391 are timed to switch high (active) when thedifferential input voltage to clocked half-rail differential logiccircuit with sense amplifier and shut-off 300A, 300B, 300C and 300Nreaches a predetermined voltage level. The clock delay can be adjustedaccording to the predetermined differential voltage level required forrobustness and the specific needs of the circuit designer. Thisdifferential voltage level is typically a function of process and willvary from circuit to circuit and system to system.

[0074] In addition, according to the invention, each clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N of cascaded chain 301 receives a second delayed clocksignal at its second clock in terminal 327A, 327B, 327C and 327N,respectively. In one embodiment of the invention, the second delayedclock signal for a given clocked half-rail differential logic circuitwith sense amplifier and shut-off 300A, 300B, 300C and 300N of cascadedchain 301 is the delayed clock signal of the following clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N in cascaded chain 301. In this embodiment of theinvention, the second delayed clock signal for a given clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N of cascaded chain 301 is provided by coupling the secondclock terminal 327A, 327B, 327C and 327N of a given clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N, respectively, to the first clock in terminal 326B, 326C,326D (not shown), 326N and 326N+1 (not shown) of the following stage300B, 300C, 300N and 300N+1 (not shown).

[0075] Thus, in FIG. 3, line 320A couples second clock in terminal 327Aof clocked half-rail differential logic circuit with sense amplifier andshut-off 300A to first clock in terminal 326B of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300B anddelay circuit 363 introduces a delay time between signal CLKA 361,coupled to first clock in terminal 326A of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, andsignal CLKB 371, coupled to second clock in terminal 327A of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300A. Likewise, line 320B couples second clock in terminal 327B ofclocked half-rail differential logic circuit with sense amplifier andshut-off 300B to first clock in terminal 326C of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300C anddelay circuit 373 introduces a delay time between signal CLKB 371,coupled to first clock in terminal 326B of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300B, andsignal CLKC 381, coupled to second clock in terminal 327B of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300B.

[0076] Similarly, line 320C couples second clock in terminal 327C ofclocked half-rail differential logic circuit with sense amplifier andshut-off 300C to first clock in terminal 326D (not shown) of a clockedhalf-rail differential logic circuit with sense amplifier and shut-off300D (not shown) and delay circuit 383 introduces a delay time betweensignal CLKC 381, coupled to first clock in terminal 326C of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300C, and signal CLKD 382, coupled to second clock in terminal 327C ofclocked half-rail differential logic circuit with sense amplifier andshut-off 300C. Likewise, line 320N couples first clock in terminal326N+1 (not shown) of a clocked half-rail differential logic circuitwith sense amplifier and shut-off 300N+1 (not shown) to second clock interminal 327N of clocked half-rail differential logic circuit with senseamplifier and shut-off 30ON and delay circuit 393 introduces a delaytime between signal CLKN 391, coupled to first clock in terminal 326N ofclocked half-rail differential logic circuit with sense amplifier andshut-off 300N, and signal CLKN+1 392, coupled to second clock interminal 327N of clocked half-rail differential logic circuit with senseamplifier and shut-off 300N.

[0077] In one embodiment of the invention, second clock in terminals327A, 327B, 327C and 327N of clocked half-rail differential logiccircuit with sense amplifier and shut-off 300A, 300B, 300C and 300N,respectively, are coupled to sense amplifiers (not shown in FIG. 3) inclocked half-rail differential logic circuit with sense amplifier andshut-off 300A, 300B, 300C and 300N, such as sense amplifier circuit 280in FIG. 2, and the signals CLKB, CLKC, CLKD, and CLKN+1 are used asdescribed above with respect to FIG. 2 to trigger the sense amplifiers(not shown in FIG. 3) in clocked half-rail differential logic circuitwith sense amplifier and shut-off 300A, 300B, 300C and 300N.

[0078]FIG. 4 is one embodiment of a timing diagram for cascaded chain301 of clocked half-rail differential logic circuits with senseamplifier and shut-off 300A, 300B, 300C and 300N of FIG. 3. As seen inFIG. 3 and FIG. 4 together, according to one embodiment of theinvention, at time T0, i.e., point T0 400A in FIG. 4, signal CLKA 461starts to go high. After a short switching delay 460, such as the shortswitching delay inherent in any circuit, signal OUTA 411A at OUTAterminal 311A starts to switch high at point 466. Corresponding signalOUTBARA at OUTBAR terminal 313A starts to discharge to low at point 467.Note that, as discussed above, points 466 and 467 typically representpotentials of approximately Vdd/2.

[0079] According to the present invention, signal CLKB 471 is delayed adelay time 472 with respect to signal CLKA 461 by delay circuit 363. Atpoint 473, i.e., time T1 400B, signal CLKB 471 starts to rise andthereby activates a sense amplifier, such as sense amplifier 280 in FIG.2, which, according to the invention, is part of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A. Oncethe sense amplifier is activated, output OUTA 411A pulls strongly tohigh starting at point 465 and reaches high point 464 rapidly. Note thedifference in the slope of signal OUTA between points 466 and 465, whenthe sense amplifier is not activated, and points 465 and 464, when thesense amplifier is activated. Likewise, corresponding signal OUTBARA413A pulls strongly low, starting at point 468, to low point 469 whenthe sense amplifier is activated.

[0080] At point 463A, in its pre-charge phase, CLKA 461 starts to switchlow. After a short delay, OUTA 411A and OUTBARA 413A begin to equalizeat points 464A and 469A, respectively, and reach approximate equilibriumat points 466A and 467A at a potential close to Vdd/2.

[0081] As also seen in FIG. 3 and FIG. 4 together, according to oneembodiment of the invention, at time T1, i.e., point T1 400B in FIG. 4,signal CLKB 471 starts to go high. After a short switching delay 470,such as the short switching delay inherent in any circuit, signal OUTB411B at OUTB terminal 311B starts to switch high at point 476.Corresponding signal OUTBARB at OUTBAR terminal 313B starts to dischargeto low at point 477. Note that, as discussed above, points 476 and 477typically represent potentials of approximately Vdd/2.

[0082] According to the present invention, signal CLKC 481 is delayed adelay time 482 with respect to signal CLKB 471 by delay circuit 373. Atpoint 483, i.e., time T2 400C, signal CLKC 481 starts to rise andthereby activates a sense amplifier, such as sense amplifier 280 in FIG.2, which, according to the invention, is part of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300B. Oncethe sense amplifier is activated, output OUTB 411B pulls strongly tohigh starting at point 475 and reaches high point 474 rapidly. Note thedifference in the slope of signal OUTB between points 476 and 475, whenthe sense amplifier is not activated, and points 475 and 474, when thesense amplifier is activated. Likewise, corresponding signal OUTBARB413B pulls strongly low, starting at point 478, to low point 479 whenthe sense amplifier is activated.

[0083] At point 473A, in its pre-charge phase, CLKB 471 starts to switchlow. After a short delay, OUTB 411B and OUTBARB 413B begin to equalizeat points 474A and 479A, respectively, and reach approximate equilibriumat points 476A and 477A at a potential close to Vdd/2.

[0084] As also seen in FIG. 3 and FIG. 4 together, according to oneembodiment of the invention, at time T2, i.e., point T2 400 c in FIG. 4,signal CLKC 481 starts to go high. After a short switching delay 480,such as the short switching delay inherent in any circuit, signal OUTC411C at OUTC terminal 311C starts to switch high at point 486.Corresponding signal OUTBARC at OUTBAR terminal 313C starts to dischargeto low at point 487. Note that, as discussed above, points 486 and 487typically represent potentials of approximately Vdd/2.

[0085] According to the present invention, signal CLKD 491 is delayed adelay time 492 with respect to signal CLKC 481 by delay circuit 383. Atpoint 493, i.e., time T3 400D, signal CLKD 491 starts to rise andthereby activates a sense amplifier, such as sense amplifier 280 in FIG.2, which, according to the invention, is part of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300C. Oncethe sense amplifier is activated, output OUTC 411C pulls strongly tohigh starting at point 485 and reaches high point 484 rapidly. Note thedifference in the slope of signal OUTC between points 486 and 485, whenthe sense amplifier is not activated, and points 485 and 484, when thesense amplifier is activated. Likewise, corresponding signal OUTBARC413C pulls strongly low, starting at point 488, to low point 489 whenthe sense amplifier is activated.

[0086] At point 483A, in its pre-charge phase, CLKC 481 starts to switchlow. After a short delay, OUTC 411C and OUTBARC 413C begin to equalizeat points 484A and 489A, respectively, and reach approximate equilibriumat points 486A and 487A at a potential close to Vdd/2.

[0087] As discussed above, according to the invention, any number ofclocked half-rail differential logic circuits with sense amplifier andshut-off 300A, 300B, 300C and 300N can be employed with cascaded chain301. In addition, the process discussed above will repeat for eachswitching of the system clock. Those of skill in the art will furtherrecognize that the choice of signal highs and signal lows was madearbitrarily in FIG. 4 for illustrative purposes only and that at othertimes, and in other embodiments of the invention, signal highs could bereplaced with signal lows and vice-versa.

[0088] As discussed above, clocked half-rail differential logic circuitwith sense amplifier and shut-off 200, 300A, 300B, 300C and 300N of theinvention include sense amplifier circuit 280 that is triggered by thedelayed clock of the following stage, i.e., the clock input to the senseamplifier circuit of the clocked half-rail differential logic circuitwith sense amplifier and shut-off of the invention is additionallydelayed with respect to the delayed clock that drives the half-raildifferential logic. The addition of the sense amplifier circuit, andsecond delayed clock signal, according to the invention, allows thesense amplifier circuit to act as the driver and therefore there is noneed for increasing the size of the logic network, or the transistorsand components making up the logic network, to provide the driverfunction. Consequently, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention are capableof operating efficiently under heavy load conditions without theincreased size and the significant reduction in speed associated withprior art half-rail differential logic circuits. In addition, theclocked half-rail differential logic circuits with sense amplifier andshut-off of the invention require less space, are simpler, dissipateless heat and have fewer components to potentially fail.

[0089] In addition, according to the present invention, clockedhalf-rail differential logic circuit with sense amplifier and shut-offinclude shut-off devices to minimize the “dip” at the high output nodethat was associated with prior art clocked half-rail differential logiccircuits. The shut-off device of the invention isolates the high outputterminal immediately from the IN terminals when the complementary OUTterminal is pulled to ground. Consequently, according to the presentinvention, the window period, or path, for the short circuit current, orcrossbar current, is significantly decreased and power is saved.

[0090] In addition, since the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention include ashut-off device, the high OUT terminal is isolated from the IN terminalsand the noise immunity of the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention issignificantly better than prior art clocked half-rail differential logiccircuits because noise on the IN terminal does not affect the high OUTterminal after evaluation. Consequently, the clocked half-raildifferential logic circuits with sense amplifier and shut-off of theinvention are better suited for application in cascaded chains.

[0091] As also discussed above, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention can becascaded together to form the chains commonly used in the industry. Whenthe clocked half-rail differential logic circuits with sense amplifierand shut-off of the invention are cascaded together, the advantages ofthe clocked half-rail differential logic circuit with sense amplifierand shut-off of the invention are particularly evident and the gains interms of efficiency, size reduction and flexibility are furtherpronounced.

[0092] The foregoing description of an implementation of the inventionhas been presented for purposes of illustration and description only,and therefore is not exhaustive and does not limit the invention to theprecise form disclosed. Modifications and variations are possible inlight of the above teachings or may be acquired from practicing theinvention.

[0093] For example, for illustrative purposes specific embodiments ofthe invention were shown with specific transistors. However, the NFETsand PFETS shown in the figures can be readily exchanged for PFETs andNFETs by reversing the polarities of the supply voltages or by otherwell known circuit modifications.

[0094] Consequently, the scope of the invention is defined by the claimsand their equivalents.

What is claimed is:
 1. A method for clock control of a cascaded chain ofclocked half-rail differential logic circuits with sense amplifier andshut-off comprising: providing a first clocked half-rail differentiallogic circuit with sense amplifier and shut-off, said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offcomprising: a first clocked half-rail differential logic circuit withsense amplifier and shut-off first clock in terminal; a first clockedhalf-rail differential logic circuit with sense amplifier and shut-offsecond clock in terminal; at least one first clocked half-raildifferential logic circuit with sense amplifier and shut-off data interminal; and at least one first clocked half-rail differential logiccircuit with sense amplifier and shut-off data out terminal; providing asecond clocked half-rail differential logic circuit with sense amplifierand shut-off, said second clocked half-rail differential logic circuitwith sense amplifier and shut-off comprising: a second clocked half-raildifferential logic circuit with sense amplifier and shut-off first clockin terminal; a second clocked half-rail differential logic circuit withsense amplifier and shut-off second clock in terminal; at least onesecond clocked half-rail differential logic circuit with sense amplifierand shut-off data in terminal; and at least one second clocked half-raildifferential logic circuit with sense amplifier and shut-off data outterminal; operatively coupling a first clock signal to said firstclocked half-rail differential logic circuit with sense amplifier andshut-off first clock in terminal; operatively coupling a second clocksignal to said second clocked half-rail differential logic circuit withsense amplifier and shut-off first clock in terminal; operativelycoupling said second clock signal to said first clocked half-raildifferential logic circuit with sense amplifier and shut-off secondclock in terminal; operatively coupling said at least one first clockedhalf-rail differential logic circuit with sense amplifier and shut-offdata out terminal to said at least one second clocked half-raildifferential logic circuit with sense amplifier and shut-off data interminal; and delaying said second clock signal with respect to saidfirst clock signal by a predetermined delay time.
 2. The method forclock control of a cascaded chain of clocked half-rail differentiallogic circuits with sense amplifier and shut-off of claim 1, furthercomprising: coupling a delay circuit between said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offclock in terminal and said second clocked half-rail differential logiccircuit with sense amplifier and shut-off clock in terminal for delayingsaid second clock signal with respect to said first clock signal by saidpredetermined delay time.
 3. The method for clock control of a cascadedchain of clocked half-rail differential logic circuits with senseamplifier and shut-off of claim 2, wherein; said delay circuit comprisesat least one inverter.
 4. The method for clock control of a cascadedchain of clocked half-rail differential logic circuits with senseamplifier and shut-off of claim 2, wherein; said first clocked half-raildifferential logic circuit with sense amplifier and shut-off comprises asense amplifier circuit coupled to said first clocked half-raildifferential logic circuit with sense amplifier and shut-off secondclock in terminal; and said second clocked half-rail differential logiccircuit with sense amplifier and shut-off comprises a sense amplifiercircuit coupled to said second clocked half-rail differential logiccircuit with sense amplifier and shut-off second clock in terminal.
 5. Amethod for clock control of a cascaded chain of clocked half-raildifferential logic circuits with sense amplifier and shut-offcomprising: providing a first supply voltage; providing a second supplyvoltage; providing a first clocked half-rail differential logic circuitwith sense amplifier and shut-off, said first clocked half-raildifferential logic circuit with sense amplifier and shut-off comprising:a first clocked half-rail differential logic circuit with senseamplifier and shut-off OUT terminal; a first clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTBARterminal; a first transistor, said first transistor comprising a firsttransistor first flow electrode, a first transistor second flowelectrode and a first transistor control electrode, said first supplyvoltage being coupled to said first transistor first flow electrode; asecond transistor, said second transistor comprising a second transistorfirst flow electrode, a second transistor second flow electrode and asecond transistor control electrode, said first transistor second flowelectrode being coupled to said second transistor first flow electrode,said second transistor second flow electrode being coupled to said firstclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal; a third transistor, said third transistorcomprising a third transistor first flow electrode, a third transistorsecond flow electrode and a third transistor control electrode, saidfirst transistor second flow electrode being coupled to said thirdtransistor first flow electrode, said third transistor second flowelectrode being coupled to said first clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal.; afourth transistor, said fourth transistor comprising a fourth transistorfirst flow electrode, a fourth transistor second flow electrode and afourth transistor control electrode, said second transistor controlelectrode being coupled to said fourth transistor first flow electrodeand said first clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal, said third transistor controlelectrode being coupled to said fourth transistor second flow electrodeand said first clocked half-rail differential logic circuit with senseamplifier and shut-off OUT terminal; a logic network, said logic networkcomprising a logic network first IN terminal, a logic network second INterminal, a logic network OUT terminal, a logic network OUTBAR terminaland a logic network fifth terminal; a fifth transistor, said fifthtransistor comprising a fifth transistor first flow electrode, a fifthtransistor second flow electrode and a fifth transistor controlelectrode, said fifth transistor first flow electrode being coupled tosaid logic network fifth terminal, said fifth transistor second flowelectrode being coupled to said second supply voltage; a first clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit coupled between said first clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal and said first clocked half-rail differential logic circuitwith sense amplifier and shut-off OUTBAR terminal, said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit having an IN terminal coupled to a second clocksignal; a first clocked half-rail differential logic circuit with senseamplifier and shut-off shut-off device coupled between said firstclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal and said first clocked half-rail differentiallogic circuit with sense amplifier and shut-off outBar terminal, saidlogic network OUT terminal being coupled to said first clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice and said logic network OUTBAR terminal being coupled to saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off shut-off device; providing a second clocked half-raildifferential logic circuit with sense amplifier and shut-off, saidsecond clocked half-rail differential logic circuit with sense amplifierand shut-off comprising: a second clocked half-rail differential logiccircuit with sense amplifier and shut-off OUT terminal; a second clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal; a first transistor, said first transistor comprising afirst transistor first flow electrode, a first transistor second flowelectrode and a first transistor control electrode, said first supplyvoltage being coupled to said first transistor first flow electrode; asecond transistor, said second transistor comprising a second transistorfirst flow electrode, a second transistor second flow electrode and asecond transistor control electrode, said first transistor second flowelectrode being coupled to said second transistor first flow electrode,said second transistor second flow electrode being coupled to said firstclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal; a third transistor, said third transistorcomprising a third transistor first flow electrode, a third transistorsecond flow electrode and a third transistor control electrode, saidfirst transistor second flow electrode being coupled to said thirdtransistor first flow electrode, said third transistor second flowelectrode being coupled to said first clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal; afourth transistor, said fourth transistor comprising a fourth transistorfirst flow electrode, a fourth transistor second flow electrode and afourth transistor control electrode, said second transistor controlelectrode being coupled to said fourth transistor first flow electrodeand said first clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal, said third transistor controlelectrode being coupled to said fourth transistor second flow electrodeand said first clocked half-rail differential logic circuit with senseamplifier and shut-off OUT terminal; a logic network, said logic networkcomprising a logic network first IN terminal, a logic network second INterminal, a logic network OUT terminal, a logic network OUTBAR terminaland a logic network fifth terminal; a fifth transistor, said fifthtransistor comprising a fifth transistor first flow electrode, a fifthtransistor second flow electrode and a fifth transistor controlelectrode, said fifth transistor first flow electrode being coupled tosaid logic network fifth terminal, said fifth transistor second flowelectrode being coupled to said second supply voltage; a second clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit coupled between said second clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal and said second clocked half-rail differential logic circuitwith sense amplifier and shut-off OUTBAR terminal, said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit having an IN terminal coupled to a third clocksignal, a second clocked half-rail differential logic circuit with senseamplifier and shut-off shut-off device coupled between said secondclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal and said second clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal, saidlogic network OUT terminal being coupled to said first clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice and said logic network OUTBAR terminal being coupled to saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off shut-off device; delaying said second clock signal withrespect to said first clock signal by a predetermined delay time; anddelaying said third clock signal with respect to said second clocksignal by a predetermined delay time.
 6. The method for clock control ofa cascaded chain of clocked half-rail differential logic circuits withsense amplifier and shut-off of claim 5, wherein; said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit comprises: a sixth transistor, said sixthtransistor comprising a sixth transistor first flow electrode, a sixthtransistor second flow electrode and a sixth transistor controlelectrode, said second transistor second flow electrode being coupled tosaid sixth transistor first flow electrode, said sixth transistor secondflow electrode being coupled to a first clocked half-rail differentiallogic circuit with sense amplifier and shut-off first node, said sixthtransistor control electrode being coupled to said fourth transistorfirst flow electrode and said first clocked half-rail differential logiccircuit with sense amplifier and shut-off OUTBAR terminal; a seventhtransistor, said seventh transistor comprising a seventh transistorfirst flow electrode, a seventh transistor second flow electrode and aseventh transistor control electrode, said third transistor second flowelectrode being coupled to said seventh transistor first flow electrode,said seventh transistor second flow electrode being coupled to saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off first node, said seventh transistor control electrode beingcoupled to said fourth transistor second flow electrode and said firstclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal; an eighth transistor, said eighth transistorcomprising an eighth transistor first flow electrode, an eighthtransistor second flow electrode and an eighth transistor controlelectrode, said eighth transistor first flow electrode being coupled tosaid first clocked half-rail differential logic circuit with senseamplifier and shut-off first node, said eighth transistor second flowelectrode being coupled to said second supply voltage, said eighthtransistor control electrode being coupled to receive said second clocksignal, further wherein; said a second clocked half-rail differentiallogic circuit with sense amplifier and shut-off sense amplifier circuitcomprises: a sixth transistor, said sixth transistor comprising a sixthtransistor first flow electrode, a sixth transistor second flowelectrode and a sixth transistor control electrode, said secondtransistor second flow electrode being coupled to said sixth transistorfirst flow electrode, said sixth transistor second flow electrode beingcoupled to a second clocked half-rail differential logic circuit withsense amplifier and shut-off first node, said sixth transistor controlelectrode being coupled to said fourth transistor first flow electrodeand said second clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal; a seventh transistor, saidseventh transistor comprising a seventh transistor first flow electrode,a seventh transistor second flow electrode and a seventh transistorcontrol electrode, said third transistor second flow electrode beingcoupled to said seventh transistor first flow electrode, said seventhtransistor second flow electrode being coupled to said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offfirst node, said seventh transistor control electrode being coupled tosaid fourth transistor second flow electrode and said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal; an eighth transistor, said eighth transistor comprising aneighth transistor first flow electrode, an eighth transistor second flowelectrode and an eighth transistor control electrode, said eighthtransistor first flow electrode being coupled to said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offfirst node, said eighth transistor second flow electrode being coupledto said second supply voltage, said eighth transistor control electrodebeing coupled to receive said third clock signal.
 7. The method forclock control of a cascaded chain of clocked half-rail differentiallogic circuits with sense amplifier and shut-off of claim 5, wherein;said first clocked half-rail differential logic circuit with senseamplifier and shut-off shut-off device comprises: a ninth transistor,said ninth transistor comprising a ninth transistor first flowelectrode, a ninth transistor second flow electrode and a ninthtransistor control electrode, said second transistor second flowelectrode being coupled to said ninth transistor first flow electrode,said ninth transistor second flow electrode being coupled to said OUTterminal of said logic network, said ninth transistor control electrodebeing coupled to said fourth transistor first flow electrode and saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off OUTBAR terminal; a tenth transistor, said tenth transistorcomprising a tenth transistor first flow electrode, a tenth transistorsecond flow electrode and a tenth transistor control electrode, saidthird transistor second flow electrode being coupled to said tenthtransistor first flow electrode, said tenth transistor second flowelectrode being coupled to said OUTBAR terminal of said logic network,said tenth transistor control electrode being coupled to said fourthtransistor second flow electrode and said first clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal, further wherein; said second clocked half-rail differentiallogic circuit with sense amplifier and shut-off shut-off devicecomprises: a ninth transistor, said ninth transistor comprising a ninthtransistor first flow electrode, a ninth transistor second flowelectrode and a ninth transistor control electrode, said secondtransistor second flow electrode being coupled to said ninth transistorfirst flow electrode, said ninth transistor second flow electrode beingcoupled to said OUT terminal of said logic network, said ninthtransistor control electrode being coupled to said fourth transistorfirst flow electrode and said second clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal; a tenthtransistor, said tenth transistor comprising a tenth transistor firstflow electrode, a tenth transistor second flow electrode and a tenthtransistor control electrode, said third transistor second flowelectrode being coupled to said tenth transistor first flow electrode,said tenth transistor second flow electrode being coupled to said OUTBARterminal of said logic network, said tenth transistor control electrodebeing coupled to said fourth transistor second flow electrode and saidsecond clocked half-rail differential logic circuit with sense amplifierand shut-off OUT terminal.
 8. The method for clock control of a cascadedchain of clocked half-rail differential logic circuits with senseamplifier and shut-off of claim 5, wherein; said logic network of saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off and said logic network of said second clocked half-raildifferential logic circuit with sense amplifier and shut-off comprisedifferential logic.
 9. The method for clock control of a cascaded chainof clocked half-rail differential logic circuits with sense amplifierand shut-off of claim 5, wherein; said logic network of said firstclocked half-rail differential logic circuit with sense amplifier andshut-off and said logic network of said second clocked half-raildifferential logic circuit with sense amplifier and shut-off comprisedifferential logic gates.
 10. The method for clock control of a cascadedchain of clocked half-rail differential logic circuits with senseamplifier and shut-off of claim 5, wherein; said logic network of saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off and said logic network of said second clocked half-raildifferential logic circuit with sense amplifier and shut-off compriseNMOS pass transistor logic; said logic network of said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offcomprises at least one control variable input and at least one passvariable input; and said logic network of said second clocked half-raildifferential logic circuit with sense amplifier and shut-off comprisesat least one control variable input and at least one pass variableinput.
 11. The method for clock control of a cascaded chain of clockedhalf-rail differential logic circuits with sense amplifier and shut-offof claim 5, wherein; said first supply voltage is Vdd and said secondsupply voltage is ground.
 12. The method for clock control of a cascadedchain of clocked half-rail differential logic circuits with senseamplifier and shut-off of claim 11, wherein; said first transistor, saidsecond transistor, and said third transistor of said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offand said first transistor, said second transistor, and said thirdtransistor of said second clocked half-rail differential logic circuitwith sense amplifier and shut-off are PFETs.
 13. The method for clockcontrol of a cascaded chain of clocked half-rail differential logiccircuits with sense amplifier and shut-off of claim 12, wherein; saidfourth transistor, said fifth transistor, said sixth transistor, saidseventh transistor, said eighth transistor, said ninth transistor andsaid tenth transistor of said first clocked half-rail differential logiccircuit with sense amplifier and shut-off and said fourth transistor,said fifth transistor, said sixth transistor, said seventh transistor,said eighth transistor, said ninth transistor and said tenth transistorof said second clocked half-rail differential logic circuit with senseamplifier and shut-off are NFETs.
 14. A method for clock control of aclocked half-rail differential logic circuit with sense amplifier andshut-off comprising: providing a first supply voltage; providing asecond supply voltage; providing a clocked half-rail differential logiccircuit with sense amplifier and shut-off OUT terminal; providing aclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal; providing a first transistor, said firsttransistor comprising a first transistor first flow electrode, a firsttransistor second flow electrode and a first transistor controlelectrode; operatively coupling said first supply voltage to said firsttransistor first flow electrode; providing a second transistor, saidsecond transistor comprising a second transistor first flow electrode, asecond transistor second flow electrode and a second transistor controlelectrode; operatively coupling said first transistor second flowelectrode to said second transistor first flow electrode; operativelycoupling said second transistor second flow electrode to said clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal; providing a third transistor, said third transistorcomprising a third transistor first flow electrode, a third transistorsecond flow electrode and a third transistor control electrode;operatively coupling said first transistor second flow electrode to saidthird transistor first flow electrode; operatively coupling said thirdtransistor second flow electrode to said clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal;providing a fourth transistor, said fourth transistor comprising afourth transistor first flow electrode, a fourth transistor second flowelectrode and a fourth transistor control electrode; operativelycoupling said second transistor control electrode to said fourthtransistor first flow electrode; operatively coupling said secondtransistor control electrode to said clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal;operatively coupling said third transistor control electrode to saidfourth transistor second flow electrode; operatively coupling said thirdtransistor control electrode to said clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal; providinga logic network, said logic network comprising a logic network first INterminal, a logic network second IN terminal, a logic network OUTterminal, a logic network OUTBAR terminal and a logic network fifthterminal; providing a fifth transistor, said fifth transistor comprisinga fifth transistor first flow electrode, a fifth transistor second flowelectrode and a fifth transistor control electrode; operatively couplingsaid fifth transistor first flow electrode to said logic network fifthterminal; operatively coupling said fifth transistor second flowelectrode to said second supply voltage; operatively coupling a clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit between said clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal and saidclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal, said clocked half-rail differential logiccircuit with sense amplifier and shut-off sense amplifier circuit havingan IN terminal; operatively coupling said clocked half-rail differentiallogic circuit with sense amplifier and shut-off sense amplifier circuitIN terminal to a second clock signal; operatively coupling a clockedhalf-rail differential logic circuit with sense amplifier and shut-offshut-off device between said clocked half-rail differential logiccircuit with sense amplifier and shut-off OUT terminal and said clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal; operatively coupling said logic network OUT terminal tosaid clocked half-rail differential logic circuit with sense amplifierand shut-off shut-off device operatively coupling said logic network OUTterminal and said logic network OUTBAR terminal to said clockedhalf-rail differential logic circuit with sense amplifier and shut-offshut-off device; and delaying said second clock signal with respect tosaid first clock signal by a predetermined time.
 15. The method forclock control of a clocked half-rail differential logic circuit withsense amplifier and shut-off of claim 14, wherein; providing saidclocked half-rail differential logic circuit with sense amplifier andshut-off sense amplifier circuit comprises: providing a sixthtransistor, said sixth transistor comprising a sixth transistor firstflow electrode, a sixth transistor second flow electrode and a sixthtransistor control electrode; operatively coupling said secondtransistor second flow electrode to said sixth transistor first flowelectrode; operatively coupling said sixth transistor second flowelectrode to a clocked half-rail differential logic circuit with senseamplifier and shut-off first node; operatively coupling said sixthtransistor control electrode to said fourth transistor first flowelectrode; operatively coupling said sixth transistor control electrodeto said clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal; providing a seventh transistor,said seventh transistor comprising a seventh transistor first flowelectrode, a seventh transistor second flow electrode and a seventhtransistor control electrode; operatively coupling said third transistorsecond flow electrode to said seventh transistor first flow electrode;operatively coupling said seventh transistor second flow electrode tosaid clocked half-rail differential logic circuit with sense amplifierand shut-off first node; operatively coupling said seventh transistorcontrol electrode to said fourth transistor second flow electrode;operatively coupling said seventh transistor control electrode to saidclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal; providing an eighth transistor, said eighthtransistor comprising an eighth transistor first flow electrode, aneighth transistor second flow electrode and an eighth transistor controlelectrode; operatively coupling said eighth transistor first flowelectrode to said clocked half-rail differential logic circuit withsense amplifier and shut-off first node; operatively coupling saideighth transistor second flow electrode to said second supply voltage;operatively coupling said eighth transistor control electrode to receivesaid second clock signal.
 16. The method for clock control of a clockedhalf-rail differential logic circuit with sense amplifier and shut-offof claim 14, wherein; providing said first clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice comprises: providing a ninth transistor, said ninth transistorcomprising a ninth transistor first flow electrode, a ninth transistorsecond flow electrode and a ninth transistor control electrode;operatively coupling said second transistor second flow electrode tosaid ninth transistor first flow electrode; operatively coupling saidninth transistor second flow electrode to said OUT terminal of saidlogic network; operatively coupling said ninth transistor controlelectrode to said fourth transistor first flow electrode; operativelycoupling said ninth transistor control electrode to said clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal; providing a tenth transistor, said tenth transistorcomprising a tenth transistor first flow electrode, a tenth transistorsecond flow electrode and a tenth transistor control electrode;operatively coupling said third transistor second flow electrode to saidtenth transistor first flow electrode; operatively coupling said tenthtransistor second flow electrode to said OUTBAR terminal of said logicnetwork; operatively coupling said tenth transistor control electrode tosaid fourth transistor second flow electrode; and operatively couplingsaid tenth transistor control electrode to said clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal
 17. The method for clock control of a clocked half-raildifferential logic circuit with sense amplifier and shut-off of claim14, wherein; said logic network of said clocked half-rail differentiallogic circuit with sense amplifier and shut-off comprises differentiallogic.
 18. The method for clock control of a clocked half-raildifferential logic circuit with sense amplifier and shut-off of claim14, wherein; said logic network of said clocked half-rail differentiallogic circuit with sense amplifier and shut-off comprises differentiallogic gates.
 19. The method for clock control of a clocked half-raildifferential logic circuit with sense amplifier and shut-off of claim14, wherein; said logic network of said clocked half-rail differentiallogic circuit with sense amplifier and shut-off comprises NMOS passtransistor logic; and said logic network of said clocked half-raildifferential logic circuit with sense amplifier and shut-off includes atleast one control variable input and at least one pass variable input.20. The method for clock control of a clocked half-rail differentiallogic circuit with sense amplifier and shut-off of claim 14, wherein;said first supply voltage is Vdd and said second supply voltage isground.
 21. The method for clock control of a clocked half-raildifferential logic circuit with sense amplifier and shut-off of claim18, wherein; said first transistor, said second transistor, and saidthird transistor are PFETs.
 22. The method for clock control of aclocked half-rail differential logic circuit with sense amplifier andshut-off of claim 19, wherein; said fourth transistor, said fifthtransistor, said sixth transistor, said seventh transistor, said eighthtransistor, said ninth transistor and said tenth transistor are NFETs.